Terrazzo surfaces are characterized by exposed marble or other aggregate chips or pieces set in a cementitious, polymer or resin matrices and are used for flooring, paneling and countertopping. Traditional marble-chip, cementitious terrazzo requires three layers of materials, i.e., a concrete foundation (typically 3 to 4 inches deep), a 2 to 3 inch deep mudbed, a relatively thin layer of sandy concrete or the like laid over the mudbed and having partially embed metal divider strips positioned therein to define joints and/or color patterns, and a fine marble chip mixture of desired colors applied into the concrete to define a terrazzo pattern. Before the layered cementitious materials set, additional marble chips of various colors may be sprinkled onto the surface. A lightweight roller is rolled over the entire surface and the material is then allowed to cure to yield a rough terrazzo surface. After curing, the rough surface is ground and then polished and sealed to prevent incursion of water and/or biohazardous material into the porosity inherent in the marble aggregate and cement matrix. The polishing and sealing processes must be repeated periodically, as terrazzo surfaces are worn down by foot traffic and the like, and even the grinding process may require repetition from time to time as damage from wear and tear dictates.
Recently, polymer-based terrazzo have become popular. Typically, the matrix material is epoxy resin, although materials, such as polyester and vinyl ester resins, may be used as the binder material. Resinous grouting has several advantages over cement grouting, such as wider color selection, thinner installation thickness, lighter weight, faster installation, impermeable finish, higher strength, and less susceptibility to cracking.
As with cementitious terrazzo, after curing, resin grouted terrazzo surfaces 10 are ground with a terrazzo grinder 12, which is roughly similar to a floor polisher, but substantially heavier. Depressions 14 left by the grinding operations are typically either ground and polished out or filled with a matching grout material and hand troweled for a smooth, uniform surface, which is then cleaned, polished, and sealed. As with traditional cementitious terrazzo, the epoxy-marble terrazzo surfaces 10 require periodic stripping, polishing and resealing due to wear. Marble and granite aggregate pieces have not been replaced with other, less porous, material such as porcelain tiles since porcelain tiles cannot be laid flat into a cementitious foundation and cannot be ground and polished flat like marble or granite, since running a heavy terrazzo grinder 12 over porcelain tiles will generate cracks in the tiles and snap off corners and edges. Further, since porcelain tiles are substantially harder than even granite, grinding the porcelain tiles down to yield a flat, terrazzo-like surface is physically difficult and economically unfeasable, as the wear on the diamond abrasives 16 would be substantially greater than for marble terrazzo and the grinding time would be substantially longer, not only substantially increasing the abrasive costs but also generating even more damage to the tiles themselves from the extended residence time of the grinder on the tiles. Thus, a need remains for a terrazzo or terrazzo-like flooring and/or surface that is inherently impermeable, that is substantially flat and smooth, and that does not require periodic maintenance. The present invention addresses this need.